A solar cell is a device which uses photovoltaic effect and directly converts light energy into electric power. At present, various solar cells using a compound semiconductor or the like as a raw material are being in practical use in addition to silicon solar cells.
A Si-crystal silicon solar cell has a structure in which solar cells are connected with each other by an interconnector via a resin such as ethylenevinylacetate (EVA) and are sandwiched between glass substrates. In a thin-film solar cell, a transparent electrode, p-type, i-type, and n-type semiconductors, an electrode, and the like are formed on a glass substrate. A thin-film compound solar cell has a structure in which an electrode layer, a photoelectric conversion layer, a buffer layer, and the like are formed on a glass substrate. Those solar cells each have a structure in which light is delivered to the cell or the photoelectric conversion layer via the glass substrate. Further, the glass substrate is used as a cover glass or a structure support (base).